Frequency synchronization, Minimal communication control, Power sharing, Series-parallel microgrids, Production of electric energy or power. Powerplants. Central stations, TK1001-1841

This paper presents a minimal-communication control scheme for series-parallel microgrids to achieve power-sharing and frequency synchronization. The proposed method involves the first distributed generators (DGs) in each string exchanging information with its neighbors using low bandwidth communication to reach a consensus. The other DGs achieve convergence through droop or inverse droop control in a communication-free manner. The proposed control scheme offers several key advantages: 1) Only the first DGs in each string exchange information using low bandwidth communication, while other DGs operate in a decentralized manner. The proposed method is a minimal communication approach. 2) The frequency synchronization is obtained under RL and RC loads. 3) Precise power sharing is achieved by regulating the output voltage amplitudes. Meanwhile, the load voltage quality is guaranteed. Furthermore, the stability analysis based on the root locus method has been demonstrated. Finally, simulations have validated the feasibility of the proposed approach.